<div id="tips">
<a id="manual" href="javascript:;">手动放烟花</a>
<a id="auto" href="javascript:;">自动放烟花</a>
</div>
<style>
html,
body {
  overflow: hidden;
}

body,
div,
p {
  margin: 0;
  padding: 0;
}

body {
  background: #000;
  font: 12px/1.5 arial;
  color: #7A7A7A;
}

a {
  text-decoration: none;
  outline: none;
}

#tips,
#copyright {
  position: absolute;
  width: 100%;
  height: 50px;
  text-align: center;
  background: #171717;
  border: 2px solid #484848;
}

#tips {
  top: 0;
  border-width: 0 0 2px;
}

#tips a {
  font: 14px/30px arial;
  color: #FFF;
  background: #F06;
  display: inline-block;
  margin: 10px 5px 0;
  padding: 0 15px;
  border-radius: 15px;
}

#tips a.active {
  background: #FE0000;
}

#copyright {
  bottom: 0;
  line-height: 50px;
  border-width: 2px 0 0;
}

#copyright a {
  color: #FFF;
  background: #7A7A7A;
  padding: 2px 5px;
  border-radius: 10px;
}

#copyright a:hover {
  background: #F90;
}

p {
  position: absolute;
  top: 55px;
  width: 100%;
  text-align: center;
}
</style>
<script>
var fgm = {
on: function (element, type, handler) {
  return element.addEventListener ? element.addEventListener(type, handler, false) : element.attachEvent("on" + type, handler)
},
un: function (element, type, handler) {
  return element.removeEventListener ? element.removeEventListener(type, handler, false) : element.detachEvent("on" + type, handler)
},
bind: function (object, handler) {
  return function () {
    return handler.apply(object, arguments)
  }
},
randomRange: function (lower, upper) { //产生范围在lower~upper的随机数
  return Math.floor(Math.random() * (upper - lower + 1) + lower)
},
getRanColor: function () { //随机获得十六进制颜色
  var str = this.randomRange(0, 0xFFFFFF).toString(16);
  while (str.length < 6) str = "0" + str;
  return "#" + str
}
};
//初始化对象
function FireWorks() {
this.type = 0;
this.timer = null;
this.fnManual = fgm.bind(this, this.manual)
}
FireWorks.prototype = {
initialize: function () {
  clearTimeout(this.timer);
  fgm.un(document, "click", this.fnManual);
  switch (this.type) {
    case 1:
      fgm.on(document, "click", this.fnManual);
      break;
    case 2:
      this.auto();
      break;
  };
},
manual: function (event) {
  event = event || window.event;
  this.__create__({
    x: event.clientX,
    y: event.clientY
  });
},

auto: function () {
  var that = this;
  that.timer = setTimeout(function () {
    that.__create__({
      x: fgm.randomRange(50, document.documentElement.clientWidth - 50),
      y: fgm.randomRange(50, document.documentElement.clientHeight - 150)
    })
    that.auto();
  }, fgm.randomRange(900, 1100))
},
__create__: function (param) {
  //param即鼠标点击点（即烟花爆炸点）
  var that = this;
  var oEntity = null;
  var oChip = null;
  var aChip = [];
  var timer = null;
  var oFrag = document.createDocumentFragment();

  oEntity = document.createElement("div");
  with (oEntity.style) { //烟花上升过程实体初始化
    position = "absolute";
    //初始位置距网页顶部为：整个网页的高度（处于网页底部）
    top = document.documentElement.clientHeight + "px";
    left = param.x + "px";
    width = "4px";
    height = "30px";
    borderRadius = "4px";
    background = fgm.getRanColor();
  };
  document.body.appendChild(oEntity);
  //window.setInterval方法 该方法使得一个函数每隔固定时间被调用一次
  //                console.log(param.y);
  oEntity.timer = setInterval(function () {
    //                    console.log(oEntity.offsetTop);
    //                    console.log(oEntity.style.top);
    oEntity.style.top = oEntity.offsetTop - 20 + "px";
    //判断烟花是否上升到或者第一次超过上次鼠标点击位置
    if (oEntity.offsetTop <= param.y) {
      //烟花爆炸
      clearInterval(oEntity.timer);
      document.body.removeChild(oEntity);
      (function () {
        //在50-100之间随机生成碎片
        //由于IE浏览器处理效率低, 随机范围缩小至20-30
        //自动放烟花时, 随机范围缩小至20-30
        var len = (/msie/i.test(navigator.userAgent) || that.type == 2) ? fgm.randomRange(20, 30) : fgm.randomRange(50, 100)
        //产生所有烟花爆炸颗粒实体
        for (i = 0; i < len; i++) {
          //烟花颗粒形态实体
          oChip = document.createElement("div");
          with (oChip.style) {
            position = "absolute";
            top = param.y + "px";
            left = param.x + "px";
            width = "4px";
            height = "4px";
            overflow = "hidden";
            borderRadius = "4px";
            background = fgm.getRanColor();
          };
          oChip.speedX = fgm.randomRange(-20, 20);
          oChip.speedY = fgm.randomRange(-20, 20);
          oFrag.appendChild(oChip);
          aChip[i] = oChip
        };
        document.body.appendChild(oFrag);
        timer = setInterval(function () {
          for (i = 0; i < aChip.length; i++) {
            var obj = aChip[i];
            with (obj.style) {
              top = obj.offsetTop + obj.speedY + "px";
              left = obj.offsetLeft + obj.speedX + "px";
            };
            obj.speedY++;
            //判断烟花爆炸颗粒是否掉落至窗体之外，为真则remove
            //splice() 方法可删除从 index 处开始的零个或多个元素
            (obj.offsetTop < 0 || obj.offsetLeft < 0 || obj.offsetTop > document.documentElement.clientHeight || obj.offsetLeft > document.documentElement.clientWidth) && (document.body.removeChild(obj), aChip.splice(i, 1))
          };
          //判断烟花爆炸颗粒是否全部remove，为真则clearInterval(timer);
          !aChip[0] && clearInterval(timer);
        }, 30)
      })()
    }
  }, 30)
}
};

fgm.on(window, "load", function () {
var oTips = document.getElementById("tips");
var aBtn = oTips.getElementsByTagName("a");
var oFireWorks = new FireWorks();

fgm.on(oTips, "click", function (event) {
  var oEvent = event || window.event;
  var oTarget = oEvent.target || oEvent.srcElement;
  var i = 0;
  if (oTarget.tagName.toUpperCase() == "A") {
    for (i = 0; i < aBtn.length; i++) aBtn[i].className = "";
    switch (oTarget.id) {
      case "manual":
        oFireWorks.type = 1;
        break;
      case "auto":
        oFireWorks.type = 2;
        break;
      case "stop":
        oFireWorks.type = 0;
        break;
    }
    oFireWorks.initialize();
    oTarget.className = "active";
    //阻止浏览器默认的事件冒泡行为
    oEvent.stopPropagation ? oEvent.stopPropagation() : oEvent.cancelBubble = true
  }
});
});
fgm.on(document, "contextmenu", function (event) {
var oEvent = event || window.event;
oEvent.preventDefault ? oEvent.preventDefault() : oEvent.returnValue = false
});

</script>